Stent Holding Fixtures

ABSTRACT

Disclosed are stent holding devices having a support mandrel and one or more stent retaining fixtures disposed on the mandrel. The retaining fixture may include a character identifier to facilitate tracking a stent mounted on the holding device. The retaining fixture may include a conical protrusion and a conical recess to allow any number of retaining fixtures to engage each other and be stacked on the mandrel. The retaining fixture may include a tubular member having a spiral cut that enables the diameter of the tubular member to be adjusted to allow for a frictional fit on the mandrel. The retaining fixture may have a Z-shaped or T-shaped structure configured to retain a stent. The stent retaining fixture may also have a filament for retaining a stent.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 13/871,952, filed onApr. 26, 2013, now U.S. Pat. No. 9,149,831, which is a divisionalapplication of U.S. application Ser. No. 11/781,181 filed on Jul. 20,2007, now U.S. Pat. No. 8,453,598, which claims the benefit of U.S.Provisional Application No. 60/807,897, filed Jul. 20, 2006, the entirecontents of which applications are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to supports for holding a stent,and more particularly, but not exclusively, relates to devices forholding a stent during manufacturing processing such as electropolishingor spray coating the stent with a beneficial agent or other coating.

BACKGROUND

Stents, grafts and a variety of other endoprosthesis are well known andused in interventional procedures, such as for treating aneurysms, forlining or repairing vessel walls, for filtering or controlling fluidflow, and for expanding or scaffolding occluded or collapsed vessels.Such endoprosthesis can be delivered and used in virtually anyaccessible body lumen of a human or animal, and can be deployed by anyvariety of recognized means. One recognized indication ofendoprosthesis, such as stents, is for the treatment of aetheroscleroticstenosis in blood vessels. For example, after a patient undergoes apercutaneous transluminal coronary angioplasty or similar interventionalprocedure, an endoprosthesis, such as a stent, is often deployed at thetreatment site to improve the results of the medical procedure and toreduce the likelihood of restenosis. The endoprosthesis is configured toscaffold or support the treated blood vessel; if desired, theendoprosthesis can also be loaded with beneficial agent so as to act asa delivery platform to reduce restenosis or the like.

Generally there are two distinct types of endoprosthesis, balloonexpandable and self-expanding endoprosthesis. A balloon expandableendoprosthesis is generally constructed of materials such as stainlesssteel, cobalt chromium or some blend thereof, wherein the stent iscrimped onto a balloon for delivery into a vessel or artery. The stentmay be plastically deformed when crimped onto the balloon and thenplastically deformed when the balloon is expanded to deploy theprosthesis. Generally balloon-expandable stents are cut from tubes andthen undergo various manufacturing processes to become a finishedproduct.

Self-expanding stents are generally fabricated from metals havingsuperelastic properties, wherein the stent pattern is cut into a tube,wherein the cut tube undergoes a series of manufacturing steps to becomea finished product.

Typically after the stent pattern has been cut into the wall of thetubing to form the stent, the stent is blasted with media to removeburs, slag and other manufacturing byproducts. After blasting, thestents are generally electropolished to create a smooth surface alongthe length of the stent as well as along the cut edges of the stent.During the electropolishing step, the stents are generally mounted on amandrel and submerged in a chemical bath to perform the polishingprocess as described in U.S. patent application Ser. No. 11/370,660(U.S. Pat. No. 8,038,803), entitled “Method of Descaling MetallicDevices,” the entirety of which is herein incorporated by reference.

After having been polished, generally the stents are ready for use andmounted on their respective delivery systems. If it is desired, thestents may be coated with a beneficial agent for release within a vesselor artery after delivery of the endoprosthesis therein. If the stent isto be coated with a coating such as a beneficial agent this is generallydone before the stent is mounted onto a delivery system.

There are various methods for applying a coating to an endoprosthesis.The most common method is to mount the endoprosthesis on a mandrel andspray a coating onto the surface of the endoprosthesis. It is preferredthat all surfaces of the endoprosthesis are covered, through this isoften difficult because the mandrel used to hold the endoprosthesisresults in a discontinuity in the surface coating which could lead tocoating failure or having the coating flake off the endoprosthesis upondelivery.

Typically when a stent has a coating applied to it, the stent must betracked during the manufacturing process for regulatory reasons. Thistracking may be performed by using numbered vials to hold the stent, ora numbered board to hold the mandrels. As production numbers increase itmay become difficult to properly track each individual stent during themanufacturing process, therefore there is a need for an improved methodand/or device for tracking a stent during production. There is also aneed for improved mandrel designs to retain an endoprosthesis duringmanufacturing and coating. The present invention satisfies these andother needs.

SUMMARY

In accordance with the present invention, there is provided a stentholding device comprising a support mandrel sized to fit in a stentlumen, and a stent retaining element removably attached to the supportmandrel, the stent retaining element including a character identifier.

In other aspects of the present invention, a stent holding devicecomprises a support mandrel sized to fit in a stent lumen, and aplurality of fixtures, each including a protruding surface that issloped relative to a longitudinal axis of the support mandrel, at leastone of the plurality of fixtures includes an aperture having a recessshaped to receive the protruding surface of another one of the pluralityof fixtures.

In further aspects of the present invention, the support mandrel extendsinto and frictionally engages the aperture of the at least one of theplurality of fixtures.

In yet other aspects of the present invention, a stent holding devicecomprises a mandrel including a segment sized to fit in a stent lumen,and a fixture removably attached to the mandrel, the fixture including aloop segment defining an inner diameter of the fixture, the innerdiameter expandable from a first size, when the fixture is removed fromthe mandrel, to a second size, when the fixture is attached to themandrel, the first size less than an outer diameter of the mandrel, thesecond size allowing for a friction fit between the loop segment and themandrel.

In detailed aspects, the fixture includes a plurality of interconnectedloop segments wrapped around the support mandrel.

In other aspects of the present invention, a stent holding apparatuscomprises a first end region, a second end region spaced apart from thefirst end region, and a stent retaining assembly disposed at the firstend region, the stent retaining assembly including two arms extendingtoward the second end region and a stent contacting member disposedbetween and attached to the two arms.

In further aspects, the stent holding apparatus comprises a second stentretaining assembly disposed at the second end region, the second stentretaining assembly including two arms extending toward the first endregion and a stent contacting member disposed between and attached tothe two arms of the second stent retaining assembly.

The stent contacting member is removably attached to the two arms inother aspects of the present invention.

In detailed aspects, the stent holding assembly is movable relative tothe second end region and is coupled to a biasing device that urges thestent holding assembly to a selected position relative to the second endregion.

The stent holding apparatus in further aspects comprises a rotationaldrive mechanism coupled to the stent retaining assembly such that thestent retaining assembly is rotated when the rotational drive mechanismis activated.

The stent holding apparatus in yet further aspects comprises a lineardrive mechanism coupled to the stent retaining assembly such that thestent retaining assembly is translated linearly when the linear drivemechanism is activated.

In other aspects of the present invention, a stent holding apparatuscomprises a support mandrel sized to fit in a stent lumen, and aZ-shaped fixture disposed on the support mandrel, the fixture includinga first protruding portion extending in a radial direction away from thesupport mandrel and a second protruding portion extending in a differentradial direction away from the support mandrel, the first and secondprotruding portions defining an outer diameter of the fixture, the outerdiameter sized such that the first and second protruding portions arecapable of engaging one or more luminal surfaces of the stent lumen.

In further aspects, the stent holding apparatus comprises anotherZ-shaped fixture disposed on the support mandrel, the fixture includinga first protruding portion extending in a radial direction away from thesupport mandrel and a second protruding portion extending in a differentradial direction away from the support mandrel, the first and secondprotruding portions defining an outer diameter of the fixture, the outerdiameter sized such that the first and second protruding portions arecapable of engaging one or more luminal surfaces of the stent lumen.

The features and advantages of the invention will be more readilyunderstood from the following detailed description which should be readin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of stent holder showing two stent retainingfixtures disposed on and spaced apart along a support mandrel.

FIG. 1B is an exploded perspective view of a stent holding deviceshowing a tracking feature removably attached to a support mandrel, thetracking feature including three stent retaining fixtures, two of thestent retaining fixtures having a numerical indicator.

FIG. 1C is a perspective view of the stent holder of FIG. 1B showing thethree stent retaining fixtures abutting each other and a stent disposedagainst a sloping surface of one of the stent retaining fixtures.

FIG. 1D is a plan view of a stent holding device showing a luer fittingabutting a fixture having a plurality of apertures, and a supportmandrel extending from the fixture.

FIGS. 1E and 1F are perspective views of a stent holding device showinga tubular member in which a spiral cut extends from a first end to asecond end of the tubular member.

FIG. 2 is a plan view of a stent holding device showing two Z-shapedstent retaining fixtures spaced apart from each other on a supportmandrel.

FIG. 3 is a plan view of a stent holding device showing a firstprotruding portion and a second protruding portion defining an outerdiameter of a stent retaining fixture.

FIG. 4 is a plan view of a stent holding device showing a supportmandrel and a luer fitting attached to one end of the support mandrel.

FIGS. 5A-5E are cross-sectional views of the support mandrel of thestent holding device of FIG. 4.

FIG. 6 is a plan view of a stent holder device showing a stent disposedbetween T-shaped stent retaining fixtures.

FIG. 7 is a perspective view of a stent holding apparatus showing twostent retaining fixtures spaced apart from each other, a support mandrelinserted into apertures formed into the two stent retaining fixtures, abiasing device and a linear drive mechanism coupled to the first stentretaining fixture, and a rotational drive mechanism coupled to the firstand second stent retaining fixtures.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinvention.

In accordance with the present invention there is provided an exemplaryembodiment of a stent holder or mandrel in accordance with the presentinvention. The stent holder in accordance with the present inventionincludes a support member and at least two stent receiving fixturesradially disposed about the support member, the receiving fixturesconfigured to retain a stent radially about the support member.

Referring now to FIG. 1A there is shown an exemplary embodiment of astent holder in accordance with the present invention. As shown in FIG.1A, the stent holder 10 includes a support mandrel 13 and two stentreceiving fixtures 15 disposed upon the support mandrel 13.

The support mandrel 13 may be embodied in the form of a needle having aluer fitting on one end and a shaft, wherein the shaft of the supportmandrel 13 may be constructed of metal or plastic. Preferably thematerial of which the support mandrel is constructed is relatively stiffand resistant to bending loads. Additionally, it is preferred that thesupport mandrel be constructed of a material which is chemicallycompatible with the coating to be applied to the stent. Also, it isdesirable that the mandrel be resistant to extreme temperatures, eitherextreme cold or extremely hot temperatures without breaking.

The support mandrel 13 is constructed having a generally circularcross-sectional profile, though other cross-sectional geometries may beutilized. For example, a section of the support mandrel 13 disposedbetween the stent receiving fixtures 15 may be cylindrical wherein thesections of the support mandrel 13 under the stent receiving fixturesmay have a different cross-sectional profile which may function as anindexing feature or locking feature for the stent receiving fixture. Forexample, the section of the support mandrel 13 configured to receive thestent receiving fixtures 15 may have a star-shaped cross-sectionalprofile (FIG. 5B) which would then index with a star-shaped aperturedisposed through the stent receiving fixture 15. It is contemplated thatother shapes may be utilized to perform the indexing as described hereinand that the shapes described above are merely exemplary.

The stent receiving fixtures 15 as shown in FIG. 1A and described hereinare constructed having an angle Φ with respect to the support mandrel13. The angle Φ may range between about zero degrees to aboutseventy-five degrees.

The stent receiving fixtures 15 have an aperture disposed therethrough,wherein the aperture is sized to receive the support mandrel 13. Asdescribed above, the aperture and the support mandrel 13 may be shapedto provide an indexing feature. Additionally, the aperture disposedthrough the receiving fixtures 15 may be a tapered aperture, therebycausing the stent receiving fixtures to be frictionally engaged with thesupport mandrel 13.

The stent receiving fixtures 15 may be constructed of plastics such asDelrin, PVC, nylon or similar materials or constructed of metal such asstainless steel, aluminum, steel, titanium or other similar metals.Additionally, the surface finish of the fixtures may range from a roughsurface to a highly polished surface.

In use, a first stent receiving fixture would be disposed upon thesupport mandrel, a stent would then be disposed radially about thesupport mandrel, the second stent receiving fixture is then placed ontothe mandrel. The stent is supported on its ends by the sloped faces ofeach of the stent receiving fixtures. The support mandrel 13 may then bemounted into a spraying apparatus where the entire assembly may berotated while being sprayed.

In some instances due to regulatory requirements it is necessary totrack specific stents through the entire manufacturing process, whereina serial number containing lot information about the beneficial agent isplaced on the products finished label. The holder shown and described inFIG. 1A may include a laser engraved number on the luer, support memberor on one or both of the stent receiving fixtures. Alternatively, themandrel 10 may be disposed on a numbered board, wherein duringmanufacture, each mandrel would be placed and removed from the samelocation on the board each time.

Referring now to FIG. 1B there is shown an embodiment of a stentreceiving fixture in accordance with the present invention. The stentreceiving fixture of FIG. 1B is similar to that described above withregard to FIG. 1A, wherein the stent receiving fixture is configured tobe radially disposed about a support member and configured at one end tohold a stent.

As shown in FIG. 1B, the stent receiving fixture 16 includes a shapedportion 17 and a body portion 18. The receiving fixture 16 may furtherinclude an identifier 14 which may be in the form of a number, letter,barcode, symbol, or other identifiable character. As shown in FIG. 1B,the shaped portion 17 of the fixture 16 is configured to either receivea stent 5 or be received by the body portion 18 of another fixture 16,wherein multiple fixtures 16 may be stacked together as shown in FIG.1C. By stacking two or more fixtures 16, it is possible to assigndistinct numbers to each holder assembly by utilizing fixtures withdifferent identifiers.

The fixtures 16 may be constructed of materials such as those describedabove with regard to the mandrel of FIG. 1A.

Referring now to FIG. 1D, there is shown another embodiment of a stentreceiving fixture in accordance with the present invention. As shown inFIG. 1D, the stent fixture is configured to be received by a supportmandrel in a manner similar to that described above. As shown, the stentfixture 20 has a first end 21 and a second end 22 wherein the first endis configured to abut a luer fitting 19 of the mandrel as shown. Thesecond end 22 of the fixture 20 is shaped to receive a stent. The shapedend 22 of the fixture 20 is shaped such that it contacts the stent in amanner that limits the area of the contact between the stent and thefixture 20. Additionally as shown, the fixture 20 includes at least oneaperture 23 formed in the body thereof and, preferably, a plurality ofapertures 23 formed in the body of the fixture 20.

In use, the apertures 23 formed in the body of the fixture 20 allow forsprayed liquid coming in contact with the fixture 20 to pass through theapertures 23 of the fixture 20 instead of flowing around the fixture 20and potentially onto the end of the stent being coated.

The fixture 20 may be formed of a metallic tubular member, wherein thefixture may be formed through laser cutting. It is also contemplatedthat the spacer be formed of the materials such as those describedabove.

Referring now to FIGS. 1E and 1F, there is shown yet another embodimentof a holder in accordance with the present invention. The holder inaccordance with FIGS. 1E and 1F comprises a generally tubular memberhaving a first end and a second end, a plurality of cuts are formedwithin the tubular member thereby allowing the diameter of the tubularmember to expand or contract.

As shown in FIG. 1E, the fixture 30 has a first end 31 and a second end32, wherein the second end 32 includes at least one extension 34extending from the second end. The extension 34 is configured to engagean end of a stent during a manufacturing process. The fixture 30 furtherincludes a cut 33 formed therein. As shown in FIGS. 1E and 1F, the cut33 is embodied as a spiral cut that wraps around the body and long thelength of the fixture 30.

The fixture 30 is configured to be disposed radially about a supportmandrel 13 as described above with regard to the mandrels in accordancewith the present invention. As shown in FIG. 1E, the fixture 30 isradially disposed about the support mandrel 13, wherein the rotating themandrel counter-clockwise expands the diameter of the fixture 30 byincreasing the spacing of the cut 33.

As shown in FIG. 1E, the fixture 30 is abutted at its first end 31against a luer 19 on the support mandrel 13, and the extension 34extending from the second end is abutted against a stent 5 that has beenradially disposed about the support mandrel.

The fixture 30 as described above, can be expanded in diameter to fittightly about the support mandrel 13 in order to position a stent 5 onthe mandrel as shown in FIG. 1E. In addition to providing positivelocation of the stent, the extension(s) 34 are designed to form a spacebetween the second end 32 of the body of the fixture and the stent 5such that, as described above, any overspray from the coating processwill not flow onto the end of the stent. Additionally, by using twofixtures, each disposed on ends of the stent, the fixture 30 can bepositioned on the support mandrel 13 to provide a force to the stent 5disposed therebetween. This force will retain the stent in a position onthe mandrel 13 as desired by the user.

In a preferred embodiment, the diameter of the fixture 30 is less thanthat of the support mandrel 13. Therefore, the diameter of the fixturemust be expanded in order to dispose the fixture over the supportmandrel 13, thereby ensuring a friction fit between the fixture 30 andthe support mandrel 13.

Referring now to FIGS. 2 and 3, there are shown other embodiments of amandrel in accordance with the present invention. As shown in FIG. 2,the mandrel 40 comprises a support mandrel 43 having fixtures 45integrally formed therein. The fixtures 45 in accordance with themandrel 40 includes a Z-shaped fixture formed from the support mandrel43, wherein the size of the fixtures and the spacing between thefixtures are selected so as to support a stent.

Referring now to FIG. 3, there is shown an embodiment of a mandrel 50 inaccordance with the present invention. The mandrel 50 in accordance withFIG. 3 is similar to the mandrel 40 of FIG. 2, wherein as shown in FIG.3, the mandrel 50 includes a fixture 55 formed of the support member 13,wherein the fixture 55 has a diameter D. The diameter D of the fixture55 is sized to frictionally retain a stent when the mandrel 50 is placedwithin a lumen of the stent.

Referring now to FIGS. 4 and 5A-5E, there is shown exemplary embodimentsof a mandrel design in accordance with the present invention. Themandrel 60 in accordance with the present invention includes a fitting19 and a support mandrel 13 as described herein in accordance with theother mandrel embodiments. The fitting 19 may be a luer fitting or anyother type of fitting that allows the mandrel to be received by anotherfixture such as an electropolishing fixture or a coating fixture.

Unlike the previously described mandrels, the mandrel in accordance withthe present embodiment does not include a separate or integrated fixtureas described above in connection with FIGS. 2 and 3. Instead, thesupport mandrel of the present embodiment is sized to retain a stentdisposed thereabout as will be described in detail below with regard toFIGS. 5A through 5E.

As shown in FIG. 5A, the support member 13 of the mandrel may have amulti-sided cross-sectional profile. The multi-sided cross-sectionalprofile may have four or more sides. As shown, when the mandrel 60A isdisposed within a stent 5, the mandrel retains the stent at multiplecontact points.

As shown in FIG. 5B, the support member 13 of the mandrel 60 may have astar-shaped cross-sectional profile. As shown, when the mandrel 60B isdisposed within a stent 5, the mandrel retains the stent at multiplecontact points.

As shown in FIG. 5C, the support member 13 of the mandrel 60 may have atriangular cross-sectional profile. As shown, when the mandrel 60 isdisposed within a stent 5, the mandrel retains the stent at multiplecontact points.

As shown in FIG. 5D, the support member 13 of the mandrel 60 may have asquare cross-sectional profile. As shown, when the mandrel 60D isdisposed within a stent 5, the mandrel retains the stent at multiplecontact points.

As shown in FIG. 5E, the support member 13 of the mandrel 60 may have aconcave-triangular cross-sectional profile. As shown, when the mandrel60E is disposed within a stent 5, the mandrel retains the stent atmultiple contact points.

In accordance with each of the embodiments described above with regardto FIGS. 5A through 5E, it is contemplated that the support mandrel 13in accordance with the mandrel 60 may have a continuous diameter alongits entire length, or alternatively, the shapes shown and describedabove may be pattered along the length of the support mandrel 13. Forexample, the shapes may be disposed along the length of the mandrel in ascrew-type fashion, disposed at intervals along the length of thesupport mandrel 13 or any combination thereof.

In other embodiments, the number of contact points can be more or lessthan the number of contact points shown in FIGS. 5A through 5E. Forexample, a six-point or seven-point star shape may be used to providesix or seven contact points, respectively. The number of contact pointsmay also vary along the length of the mandrel 13. The number, size,shape, and configuration of contact points may be selected according toneed. For example, a particular number, size, shape, and configurationof contact points may be needed to mask an inner surface area of a stentduring a coating process. Additionally, a particular number, size,shape, and configuration of contact points may be needed to facilitateproper air mixing or drying.

Referring now to FIG. 6, there is shown an embodiment of a mandrel inaccordance with embodiments of the present invention. As shown in FIG.6, the mandrel 80 includes a support member 13, a hub or luer 19, and atleast one stent fixture 82. The stent fixture 82 as shown in FIG. 6 isconfigured to engage an end portion of a stent 5 as shown. The stentfixture 82 is preferably embodied as having a T-shape as shown.

Referring now to FIG. 7, there is shown an mandrel 70 and associatedfixturing in accordance with the embodiments of present invention. Themandrel and fixture shown in FIG. 7 includes a left fixture and a rightfixture as well as a tension adjustment mechanism and drive mechanism.The mandrel 70 of the present embodiment does not require a supportmandrel, though one may be used as shown in FIG. 7.

In FIG. 7, the mandrel 70 includes a right mandrel assembly 75 a and aleft mandrel assembly 75 b. The left and right mandrel assemblies 75 a,75 b include similar components as will be described below andreferenced with the same reference numbers.

The left and right mandrel assemblies 75 a, 75 b each include a stentretaining fixture comprised of two components, a plurality of arms 72,72′ and a stent contacting member 73, 73′ disposed between the two arms.The stent contacting member may be embodied in the form of a threadedmember such as a piece of suture, or a metallic member such as a wire orother similar types of materials that may be disposed between the twoarms 72, 72′. The stent contacting member 73, 73′ may also be configuredto be easily removed from the arms 72, 72′, wherein the stent contactingmember 73, 73′ may be replaced after a process has been performed on thestent to reduce the possibility of contamination or failure. The arms72, 72′ are attached to a shaft member 71, 71′ which is supported by ahousing 74 as shown.

The right mandrel assembly 75 a further includes a drive mechanismconfigured to provide rotational movement to the shaft member 71.Additionally, the shaft member 71 of the right mandrel assembly mayfurther include an aperture disposed therethrough, wherein a supportmandrel 13 may be disposed therethrough to aid in loading a stentbetween the two mandrel assemblies 75 a, 75 b.

The left mandrel assembly 75 b further includes a drive mechanismcoupled to the shaft member 71′ and configured to provide rotationalmotion to the shaft member 71′. The left mandrel assembly 75 b furtherincludes a linear drive mechanism 77 coupled to the shaft member 71′,wherein the linear drive mechanism is utilized to adjust the distancebetween the left mandrel assembly and the right mandrel assembly whenstent 5 is placed between the two assemblies 75 a, 75 b. As shown inFIG. 7, the left mandrel assembly 75 b may further include a biasingmember 79, such as a spring, which acts on the shaft 71′. The biasingmember 79 may act on the shaft 71′ in combination with the linear drivemember 77 or opposed to the linear drive member 77.

In use the stent 5 is placed between the left mandrel assembly 75 b andthe right mandrel assembly 75 a, a support mandrel 13 is advancedthrough an aperture in the right mandrel assembly 75 a and through thestent 5, wherein the distal end of the support mandrel 13 is received bythe shaft 71′ of the left mandrel assembly 75 b. The distance betweenthe two mandrel assemblies 75 a, 75 b is adjusted by moving the leftmandrel assembly 75 b, wherein the ends of the stent 5 are supported bythe stent contacting members 73, 73′. The support mandrel 13 is thenremoved from the lumen of the stent and the right mandrel assembly 75 a.Each of the rotational drive assemblies are then engaged to providerotation to the mandrel assemblies and the stent. Preferably, therotational drive assemblies are coupled together, thereby providinguniform rotational motion to the stent retained between the two mandrelassemblies.

It shall be understood that the arms 72, 72′ and the stent contactingmembers 73, 73′ may be replaced by any of the other mandrels inaccordance with the above embodiments shown and described herein withreference to the present invention.

Although the mandrels and methods of use in accordance with the presentinvention have been described in accordance with stent coating, it willbe understood by one of ordinary skill in the art that the mandrels inaccordance with the present invention may be utilized for otherpurposes. For example, the mandrels may be utilized duringelectropolishing procedures, manufacturing procedures, storage or forsimilar purposes.

Referring again to FIGS. 1B and 1C, there is shown a stent holdingdevice comprising a support mandrel 13 sized to fit in the lumen of astent 5. Also shown is a plurality of stent retaining elements orfixtures 16, each including a character identifier 14. The characteridentifier can be a numeral (as shown), an alphabetic character, otherreadily recognizable symbol, or a combination thereof. The fixtures 16are arranged longitudinally in series on the mandrel. The combination ofidentifiers 14 on the fixtures 16 provides a unique identifier fortracking a stent mounted on the stent holding device during a coatingprocess or other manufacturing process. In the illustrated embodiment,the fixtures 16 provide the stent holding device with the numericalidentifier of “21.” Although three fixtures 16 are shown on the mandrel13, any number fixtures may be used to provide a desired uniqueidentifier. For example, if it is desired to assign a stent with theunique identifier “357A,” four fixtures 16 can be arranged in series onthe mandrel, with the first, second, third, and fourth fixtures havingthe identifiers of “3,” “5,” “7,” and “A,” respectively.

In addition to or as an alternative to a character identifiers, thefixtures 16 may include barcodes, other machine readable graphics, orRFID devices embedded in or mounted on the fixtures 16. The use of acharacter identifier, such as a numeral, has the advantage of beingreadily recognizable by persons handling the stent without the aid ofbarcode reading devices, RFID scanners, or other machines.

As shown in FIG. 1B, each of the plurality of stent retaining fixtures16 includes a sloped surface 17 that protrudes from the main cylindricalbody 18 of the fixture 16. The sloped surface 17 is conical and issloped relative to a longitudinal axis 100 of the support mandrel 13.Although not visible in FIG. 1B, the second (middle) fixture 16 includesa tapered aperture shaped to receive the sloped surface 17 of the firstfixture 16 located furthest away from the stent 5. Also, the thirdfixture 16, located closest to the stent 5, includes a tapered aperture102 shaped to receive the sloped surface 17 of the second fixture 16.The tapered aperture 102 includes a conical recess portion that extendsinto the body 18 and a longitudinal bore that extends beneath the slopedsurface 17. Preferably, the recess of the tapered aperture 102 has ashape that corresponds to the shape of the sloped surface 17 so as toallow adjacent fixtures 16 to matingly engage each other. The mandrel 13extends through and frictionally engages the tapered aperture 102 of thefixtures 16. In this way, the fixtures 16 are prevented frominadvertently sliding off the mandrel 13.

The ability to add and remove fixtures 16 also facilitates mounting morethan one stent on the stent holding device. For example, two fixtures 16may be used to separate two stents disposed on the support mandrel 13.The two fixtures can be oriented in opposite directions such that theirrespective sloped surface faces toward and engages an adjacent stentedge.

Referring again to FIGS. 1E and 1F, there is shown a stent holdingdevice comprising a support mandrel 13 including a segment sized to fitin the lumen of a stent 5. A fixture 30 is removably attached to anouter diameter of the mandrel 13. The fixture 30 includes a plurality ofinterconnected loop segments 110. The loop segments 110 are attached tothe support mandrel. The loop segments 110 define an inner diameter 112that is expandable from a first size to a second size. The first size isless than an outer diameter 114 of the support mandrel 13. The innerdiameter 112 has the first size when the fixture 30 is removed from thesupport mandrel 13. The second size allows for a frictional fit betweenthe loop segments 110 and the support mandrel 13. A frictional fit canbe achieved with an inner diameter 112 that is equal in size to theouter diameter 114 of the mandrel 13. The inner diameter 112 has thesecond size when the fixture 30 is attached to the support mandrel 13,as shown in FIGS. 1E and 1F.

FIGS. 1E and 1F also show a tubular member 116 including a first end 31,a second end 32, and a spiral cut 33 formed in the tubular member. Thespiral cut 33 extends from the first end 31 to the second end 32 suchthat the inner diameter 112 of the tubular member is expandable from thefirst size to the second size. The tubular member 116 can, for example,be formed of a flat spring or other resilient member that is coiled in ahelical manner such that its inner diameter 112 tends to have the firstsize. The coiled spring of the tubular member 116 is configured suchthat twisting or longitudinally compressing the coiled spring forces theinner diameter to expand from the first size to the second size.

Referring once again to FIGS. 2 and 3, there is shown a stent holdingdevice comprising a support mandrel 43 sized to fit in a stent lumen,and two Z-shaped fixtures 45 disposed on the mandrel 43 and spaced apartfrom each other by a distance selected to allow the fixtures to engageopposing end regions of a stent. Each of the fixtures 45 includes afirst protruding portion 130 and a second protruding portion 132. Thefirst protruding portion 132 extends in a radial direction 134 away fromthe support mandrel 43. The second protruding portion 134 extends in adifferent radial direction 136 from the support mandrel 43. The radialdirections 134, 136 are opposite or 180 degrees from each other;however, the radial directions 134,136 may be at other angles relativeto each other. The first and second protruding portions 130, 132 definean outer diameter D of the fixture 45. The outer diameter D is sizedsuch that the first and second protruding portions 130, 132 engage oneor more luminal or inward facing surfaces of a stent lumen.

Referring again to FIG. 7, there is shown a stent holding apparatus 70comprising a first region 140, a second end region 142 spaced apart fromthe first end region, a first stent retaining assembly or fixture 144disposed at the first end region, and a second stent retaining fixture146 disposed at the second end region. Each of the stent retainingfixtures 144, 146 includes two arms 72, 72′ and a stent contactingmember 73, 73′ disposed between and attached to the two arms. The stentcontacting member 73, 73′ is formed of one or more filaments. Examplesof a suitable filament include, without limitation, a suture, a metalwire, a threaded member, an elastic band, or a flexible pin. The stentcontacting member 73, 73′ can be removably attached to the ends of thearms in a manner that allows the stent contacting member 73, 73′ to bedetached and replaced whenever necessary.

The stent holding apparatus 70 optionally includes a support mandrel 13sized to fit into a stent lumen and disposed between the first andsecond end regions 140, 142. In the illustrated embodiment, a portion ofthe support mandrel 13 extends from the first end region 140 and beyondthe second end region 142. The support mandrel 13 is movable inlongitudinal directions 150 through an aperture 148 formed in each ofthe fixtures 144, 146.

Still referring to FIG. 7, the first stent retaining fixture 144 ismovable relative to the second end region 142, thereby allowing thefirst stent retaining fixture 144 to be moved closer or further from thesecond stent retaining fixture 146 as needed to allow for installationand removal of a stent and to accommodate and retain stents of differingsizes. The first stent retaining fixture is coupled to a biasing device79 that urges the stent retaining fixture to a selected positionrelative to the second end region 142. An example of a suitable biasingdevice includes, without limitation, a spring.

In FIG. 7, the stent 5 is shown temporarily supported by the mandrel 13prior to being supported by the stent contacting members 73, 73′. Whenthe first stent retaining fixture 144 is linearly translated to theright, the stent 5 comes into contact with and is retained by the stentcontacting members 73, 73′. Then, the mandrel 13 may be pulled out ofthe stent holding apparatus 70.

A linear drive mechanism 77, which can comprise gears 152, is coupled tothe first stent retaining fixture 144 such that the fixture istranslated linearly in a longitudinal direction when the linear drivemechanism is activated. A rotational drive mechanism 154 is coupled tothe first and second stent retaining fixtures 144, 146 such that thestent retaining fixtures are rotated when the rotational drive mechanismis activated.

While several particular forms of the invention have been illustratedand described, it will also be apparent that various modifications canbe made without departing from the scope of the invention. It is alsocontemplated that various combinations or subcombinations of thespecific features and aspects of the disclosed embodiments can becombined with or substituted for one another in order to form varyingmodes of the invention. Accordingly, it is not intended that theinvention be limited, except as by the appended claims.

What is claimed is:
 1. A stent holding device comprising: a supportmandrel sized to fit in a stent lumen; and a stent retaining elementremovably attached to the support mandrel, the stent retaining elementincluding a character identifier.
 2. The stent holding device of claim1, further comprising a plurality of stent retaining elements, whereineach of the plurality of stent retaining elements includes a protrudingsurface that is sloped relative to a longitudinal axis of the supportmandrel, and at least one of the plurality of stent retaining elementsincludes an aperture having a tapered recess shaped to receive theprotruding surface of another one of the plurality of stent retainingelements.
 3. The stent holding device of claim 2, wherein the supportmandrel extends through and frictionally engages the aperture of the atleast one of the plurality of stent retaining elements.
 4. The stentholding device of claim 1, wherein the stent retaining element includesa tubular member including a first end, a second end, and a spiral cutformed in the tubular member and extending from the first end to thesecond end such that an inner diameter of the tubular member isexpandable from a first size to a second size, the first size being lessthan an outer diameter of the support mandrel, the second size allowingfor a friction fit between the tubular member and the support mandrel.5. The stent holding device of claim 1, further comprising a luerfitting attached to one end of the support mandrel.
 6. The stent holdingdevice of claim 1, wherein the stent retaining element includes a firstarm extending in a radial direction away from the support mandrel, asecond arm extending in a different radial direction away from thesupport mandrel, and a stent contacting member disposed between andattached to the first and second arms, the stent contacting memberformed of one or more filaments or formed of a flexible member.
 7. Thestent holding device of claim 1, wherein the stent retaining elementincludes a Z-shaped structure including a first protruding portionextending in a radial direction away from the support mandrel and asecond protruding portion extending in a different radial direction awayfrom the support mandrel, the first and second protruding portionsdefining an outer diameter of the stent retaining element, the outerdiameter sized such that the first and second protruding portions arecapable of engaging one or more luminal surfaces of the stent lumen. 8.A stent holding device comprising: a support mandrel sized to fit in astent lumen; and a plurality of fixtures, each including a protrudingsurface that is sloped relative to a longitudinal axis of the supportmandrel, at least one of the plurality of fixtures includes an aperturehaving a tapered recess shaped to receive the protruding surface ofanother one of the plurality of fixtures.
 9. The stent holding device ofclaim 8, wherein the support mandrel extends into and frictionallyengages the aperture of the at least one of the plurality of fixtures.10. The stent holding device of claim 8, wherein the at least one of theplurality of stent retaining fixtures includes a character identifier.